Yes, I'd recommend the night tour. I really enjoyed it. You get to see two unusual wildlife spectacles that time of day. Swarms of parakeets who, oddly, live at the crater return at sunset. They've adapted to the sulfuric fumes and can roost there at night. Swarms of bats leave their caves at night. They also take you on a trail where you can peer into the crater and see the glowing rock. They use the term "lava," but it's not molten lava like at a volcano in Hawaii. Still, it's an impressive sight. If anything else, the temps are just cooler there as the sun starts to go down.

In theory, the tour is offered every night, but if there's not a minumum number of people signed up, they might cancel it. Check with whatever tour operator you're using. If the sulfur levels are too high, they'll also not permit visitors into the park. I think that's a rare occurrence. Any time, though, it's very much a "rotten egg" smell.